The present invention relates to a projection display apparatus for separating a white light beam from a light source into three colored light beams, specifically red, blue, and green, passing each of these colored light beams through a light valve composed of a liquid crystal panel for modulation according to the image information, and then after modulation recombining the modulated light beams of each color through a projection lens for projection enlargements to a screen. More specifically, the present invention relates to the arrangement of the components comprising such a projection display apparatus.
A projection display apparatus basically comprises a light source lamp unit, an optical lens unit, a projection lens unit, a power supply unit, and a circuit board group on which the control circuitry, etc., is mounted. The white light beam emitted from the light source lamp unit is optically processed by the optical lens unit to synthesize a color image according to the image information. After processing, the combined light beam is projected by the projection lens unit onto a screen.
Except for the projection lens unit, each of these components is disposed within the apparatus"" outside case. The projection lens unit is mounted with the front thereof projecting from the front of the apparatus. An operating panel with the power switch, etc., and a receptor window for the remote control, are disposed on the outer surface of the outside case.
If this type of projection display apparatus was made compact and light weight to ease its transportation, it would be possible to view color images on a large screen in any desired location, which would be convenient.
However, the various units assembled inside a conventional projection display apparatus are arranged on the same horizontal plane. As a result, the length and width of the apparatus are large and it is therefore inconvenient to transport. When this projection display apparatus is placed on a table or desk, it occupies a large area, which is also inconvenient.
The likelihood of dropping the apparatus or colliding with walls, etc., it also increased when this projection display apparatus is transported. When the apparatus is impacted as a result of dropping or collision, the optical elements of the internal optical lens unit may become misaligned with each other, and the optical lens unit and light source lamp unit may become offset from each other. This may prevent appropriate color synthesis by the optical lens unit, resulting in color irregularities and lighting irregularities, and thus degraded projection image quality.
There are also projection display apparatuses including a drive unit for reading a floppy disk. PCMCIA card, or other recording medium, and constructed to form projection images corresponding to the read information. Appropriately positioning the drive unit in this type of projection display apparatus is important to reduce the size of the apparatus.
An object of the present invention is to reduce the length and width of the projection display apparatus by appropriately positioning within the outside case the various units comprising the projection display apparatus.
Another object of the present invention is to avoid deterioration of the projection image quality as a result of a misalignment occurring between the various units and between the optical elements in the units as a result of the projection display apparatus being impacted by dropping, collision, etc.
A further object of the present invention is to avoid increasing the size of a projection display apparatus by including a drive unit for reading a floppy disk, PCMCIA card, or other recording medium by appropriately positioning the drive unit.
To achieve the above objects in a projection display apparatus including: a light source lamp unit; an optical lens unit comprising a color separation means for separating the white light beam emitted from the light source lamp unit into colored light beams of the three primary colors, three light valves for modulating the light beams of each of the separated colors, and a color synthesis means for combining the modulated light beams of each of the modulated colors; a projection lens unit for projecting the combined modulated light beams onto a screen; a power supply unit; and an outside case in which each of the preceding units is assembled, the present invention positions the projection lens unit in the front part of the outside case, positions the light source lamp unit in the back part of the outside case, and positions the optical lens unit and power supply unit stacked vertically between the projection lens unit and light source lamp unit.
With this configuration, the large optical lens unit and power supply unit overlap vertically and, as a result, the length and width of the overall apparatus can be reduced.
In general, the power supply unit is positioned below the optical lens unit. The center of gravity of the apparatus is therefore low because the heavy power supply unit is positioned at the bottom when thus configures. As a result, the apparatus is stable when placed on a table, etc., and movement of the internal parts is less likely even when an impact force is applied to the side.
In addition to the above configuration, the optical lens unit may be constructed with a head panel as a structural member extending sideways or transversely in the apparatus with a horizontal panel part of the head panel also functioning as at least part of the shield case covering the power supply unit. When thus constructed, the apparatus can be made smaller and more compact by the amount both parts are used in common.
In a projection display apparatus that includes a drive unit for reading an information recording medium, the present invention uses a construction in which the drive unit is disposed between the bottom panel part of the outside case and the light source lamp unit. The present invention uses an arrangement in which the power supply unit and optical lens unit are vertically overlapping as described above. The height of these overlapping units is normally greater than the height of the light source lamp unit. As a result, dead space can be formed below the light source lamp unit. If this dead space is used to hold the drive unit, the size of the apparatus need not be increased to provide a drive unit.
Alternatively, the drive unit may be placed below the optical lens unit in an area not occupied by the power supply unit.
The light source lamp unit may also be fixed to, or formed as a single unit with, the optical lens unit in the present invention. In addition to this configuration, the light source lamp unit and projection unit are fixed to the head panel, which is a structural member of the optical lens unit. By using this configuration, the various units can be fastened together or integrated, and the overall rigidity can be increased. The optical axis will therefore not be offset between each of the units even when an impact force acts on the apparatus as a result of dropping or collision, etc. It is also possible to avoid misalignment between the optical elements in each unit.
A cooling fan is also disposed above the three light valve panels and optical lens unit in the present invention with air holes formed in the head panel to enable the forced air from the cooling fan to enter the optical lens unit, and intake holes formed in the power supply unit. With this configuration, the apparatus can be made small and compact, and the power supply unit can be efficiently cooled.